1 /*
2  * videobuf2-core.c - video buffer 2 core framework
3  *
4  * Copyright (C) 2010 Samsung Electronics
5  *
6  * Author: Pawel Osciak <pawel@osciak.com>
7  *	   Marek Szyprowski <m.szyprowski@samsung.com>
8  *
9  * The vb2_thread implementation was based on code from videobuf-dvb.c:
10  *	(c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation.
15  */
16 
17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 
19 #include <linux/err.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/mm.h>
23 #include <linux/poll.h>
24 #include <linux/slab.h>
25 #include <linux/sched.h>
26 #include <linux/freezer.h>
27 #include <linux/kthread.h>
28 
29 #include <media/videobuf2-core.h>
30 #include <media/v4l2-mc.h>
31 
32 #include <trace/events/vb2.h>
33 
34 static int debug;
35 module_param(debug, int, 0644);
36 
37 #define dprintk(level, fmt, arg...)				\
38 	do {							\
39 		if (debug >= level)				\
40 			pr_info("%s: " fmt, __func__, ## arg);	\
41 	} while (0)
42 
43 #ifdef CONFIG_VIDEO_ADV_DEBUG
44 
45 /*
46  * If advanced debugging is on, then count how often each op is called
47  * successfully, which can either be per-buffer or per-queue.
48  *
49  * This makes it easy to check that the 'init' and 'cleanup'
50  * (and variations thereof) stay balanced.
51  */
52 
53 #define log_memop(vb, op)						\
54 	dprintk(2, "call_memop(%p, %d, %s)%s\n",			\
55 		(vb)->vb2_queue, (vb)->index, #op,			\
56 		(vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
57 
58 #define call_memop(vb, op, args...)					\
59 ({									\
60 	struct vb2_queue *_q = (vb)->vb2_queue;				\
61 	int err;							\
62 									\
63 	log_memop(vb, op);						\
64 	err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0;		\
65 	if (!err)							\
66 		(vb)->cnt_mem_ ## op++;					\
67 	err;								\
68 })
69 
70 #define call_ptr_memop(vb, op, args...)					\
71 ({									\
72 	struct vb2_queue *_q = (vb)->vb2_queue;				\
73 	void *ptr;							\
74 									\
75 	log_memop(vb, op);						\
76 	ptr = _q->mem_ops->op ? _q->mem_ops->op(args) : NULL;		\
77 	if (!IS_ERR_OR_NULL(ptr))					\
78 		(vb)->cnt_mem_ ## op++;					\
79 	ptr;								\
80 })
81 
82 #define call_void_memop(vb, op, args...)				\
83 ({									\
84 	struct vb2_queue *_q = (vb)->vb2_queue;				\
85 									\
86 	log_memop(vb, op);						\
87 	if (_q->mem_ops->op)						\
88 		_q->mem_ops->op(args);					\
89 	(vb)->cnt_mem_ ## op++;						\
90 })
91 
92 #define log_qop(q, op)							\
93 	dprintk(2, "call_qop(%p, %s)%s\n", q, #op,			\
94 		(q)->ops->op ? "" : " (nop)")
95 
96 #define call_qop(q, op, args...)					\
97 ({									\
98 	int err;							\
99 									\
100 	log_qop(q, op);							\
101 	err = (q)->ops->op ? (q)->ops->op(args) : 0;			\
102 	if (!err)							\
103 		(q)->cnt_ ## op++;					\
104 	err;								\
105 })
106 
107 #define call_void_qop(q, op, args...)					\
108 ({									\
109 	log_qop(q, op);							\
110 	if ((q)->ops->op)						\
111 		(q)->ops->op(args);					\
112 	(q)->cnt_ ## op++;						\
113 })
114 
115 #define log_vb_qop(vb, op, args...)					\
116 	dprintk(2, "call_vb_qop(%p, %d, %s)%s\n",			\
117 		(vb)->vb2_queue, (vb)->index, #op,			\
118 		(vb)->vb2_queue->ops->op ? "" : " (nop)")
119 
120 #define call_vb_qop(vb, op, args...)					\
121 ({									\
122 	int err;							\
123 									\
124 	log_vb_qop(vb, op);						\
125 	err = (vb)->vb2_queue->ops->op ?				\
126 		(vb)->vb2_queue->ops->op(args) : 0;			\
127 	if (!err)							\
128 		(vb)->cnt_ ## op++;					\
129 	err;								\
130 })
131 
132 #define call_void_vb_qop(vb, op, args...)				\
133 ({									\
134 	log_vb_qop(vb, op);						\
135 	if ((vb)->vb2_queue->ops->op)					\
136 		(vb)->vb2_queue->ops->op(args);				\
137 	(vb)->cnt_ ## op++;						\
138 })
139 
140 #else
141 
142 #define call_memop(vb, op, args...)					\
143 	((vb)->vb2_queue->mem_ops->op ?					\
144 		(vb)->vb2_queue->mem_ops->op(args) : 0)
145 
146 #define call_ptr_memop(vb, op, args...)					\
147 	((vb)->vb2_queue->mem_ops->op ?					\
148 		(vb)->vb2_queue->mem_ops->op(args) : NULL)
149 
150 #define call_void_memop(vb, op, args...)				\
151 	do {								\
152 		if ((vb)->vb2_queue->mem_ops->op)			\
153 			(vb)->vb2_queue->mem_ops->op(args);		\
154 	} while (0)
155 
156 #define call_qop(q, op, args...)					\
157 	((q)->ops->op ? (q)->ops->op(args) : 0)
158 
159 #define call_void_qop(q, op, args...)					\
160 	do {								\
161 		if ((q)->ops->op)					\
162 			(q)->ops->op(args);				\
163 	} while (0)
164 
165 #define call_vb_qop(vb, op, args...)					\
166 	((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
167 
168 #define call_void_vb_qop(vb, op, args...)				\
169 	do {								\
170 		if ((vb)->vb2_queue->ops->op)				\
171 			(vb)->vb2_queue->ops->op(args);			\
172 	} while (0)
173 
174 #endif
175 
176 #define call_bufop(q, op, args...)					\
177 ({									\
178 	int ret = 0;							\
179 	if (q && q->buf_ops && q->buf_ops->op)				\
180 		ret = q->buf_ops->op(args);				\
181 	ret;								\
182 })
183 
184 #define call_void_bufop(q, op, args...)					\
185 ({									\
186 	if (q && q->buf_ops && q->buf_ops->op)				\
187 		q->buf_ops->op(args);					\
188 })
189 
190 static void __vb2_queue_cancel(struct vb2_queue *q);
191 static void __enqueue_in_driver(struct vb2_buffer *vb);
192 
193 /*
194  * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
195  */
196 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
197 {
198 	struct vb2_queue *q = vb->vb2_queue;
199 	void *mem_priv;
200 	int plane;
201 	int ret = -ENOMEM;
202 
203 	/*
204 	 * Allocate memory for all planes in this buffer
205 	 * NOTE: mmapped areas should be page aligned
206 	 */
207 	for (plane = 0; plane < vb->num_planes; ++plane) {
208 		/* Memops alloc requires size to be page aligned. */
209 		unsigned long size = PAGE_ALIGN(vb->planes[plane].length);
210 
211 		/* Did it wrap around? */
212 		if (size < vb->planes[plane].length)
213 			goto free;
214 
215 		mem_priv = call_ptr_memop(vb, alloc,
216 				q->alloc_devs[plane] ? : q->dev,
217 				q->dma_attrs, size, q->dma_dir, q->gfp_flags);
218 		if (IS_ERR_OR_NULL(mem_priv)) {
219 			if (mem_priv)
220 				ret = PTR_ERR(mem_priv);
221 			goto free;
222 		}
223 
224 		/* Associate allocator private data with this plane */
225 		vb->planes[plane].mem_priv = mem_priv;
226 	}
227 
228 	return 0;
229 free:
230 	/* Free already allocated memory if one of the allocations failed */
231 	for (; plane > 0; --plane) {
232 		call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
233 		vb->planes[plane - 1].mem_priv = NULL;
234 	}
235 
236 	return ret;
237 }
238 
239 /*
240  * __vb2_buf_mem_free() - free memory of the given buffer
241  */
242 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
243 {
244 	unsigned int plane;
245 
246 	for (plane = 0; plane < vb->num_planes; ++plane) {
247 		call_void_memop(vb, put, vb->planes[plane].mem_priv);
248 		vb->planes[plane].mem_priv = NULL;
249 		dprintk(3, "freed plane %d of buffer %d\n", plane, vb->index);
250 	}
251 }
252 
253 /*
254  * __vb2_buf_userptr_put() - release userspace memory associated with
255  * a USERPTR buffer
256  */
257 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
258 {
259 	unsigned int plane;
260 
261 	for (plane = 0; plane < vb->num_planes; ++plane) {
262 		if (vb->planes[plane].mem_priv)
263 			call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
264 		vb->planes[plane].mem_priv = NULL;
265 	}
266 }
267 
268 /*
269  * __vb2_plane_dmabuf_put() - release memory associated with
270  * a DMABUF shared plane
271  */
272 static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
273 {
274 	if (!p->mem_priv)
275 		return;
276 
277 	if (p->dbuf_mapped)
278 		call_void_memop(vb, unmap_dmabuf, p->mem_priv);
279 
280 	call_void_memop(vb, detach_dmabuf, p->mem_priv);
281 	dma_buf_put(p->dbuf);
282 	p->mem_priv = NULL;
283 	p->dbuf = NULL;
284 	p->dbuf_mapped = 0;
285 }
286 
287 /*
288  * __vb2_buf_dmabuf_put() - release memory associated with
289  * a DMABUF shared buffer
290  */
291 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
292 {
293 	unsigned int plane;
294 
295 	for (plane = 0; plane < vb->num_planes; ++plane)
296 		__vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
297 }
298 
299 /*
300  * __setup_offsets() - setup unique offsets ("cookies") for every plane in
301  * the buffer.
302  */
303 static void __setup_offsets(struct vb2_buffer *vb)
304 {
305 	struct vb2_queue *q = vb->vb2_queue;
306 	unsigned int plane;
307 	unsigned long off = 0;
308 
309 	if (vb->index) {
310 		struct vb2_buffer *prev = q->bufs[vb->index - 1];
311 		struct vb2_plane *p = &prev->planes[prev->num_planes - 1];
312 
313 		off = PAGE_ALIGN(p->m.offset + p->length);
314 	}
315 
316 	for (plane = 0; plane < vb->num_planes; ++plane) {
317 		vb->planes[plane].m.offset = off;
318 
319 		dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
320 				vb->index, plane, off);
321 
322 		off += vb->planes[plane].length;
323 		off = PAGE_ALIGN(off);
324 	}
325 }
326 
327 /*
328  * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
329  * video buffer memory for all buffers/planes on the queue and initializes the
330  * queue
331  *
332  * Returns the number of buffers successfully allocated.
333  */
334 static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
335 			     unsigned int num_buffers, unsigned int num_planes,
336 			     const unsigned plane_sizes[VB2_MAX_PLANES])
337 {
338 	unsigned int buffer, plane;
339 	struct vb2_buffer *vb;
340 	int ret;
341 
342 	/* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
343 	num_buffers = min_t(unsigned int, num_buffers,
344 			    VB2_MAX_FRAME - q->num_buffers);
345 
346 	for (buffer = 0; buffer < num_buffers; ++buffer) {
347 		/* Allocate videobuf buffer structures */
348 		vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
349 		if (!vb) {
350 			dprintk(1, "memory alloc for buffer struct failed\n");
351 			break;
352 		}
353 
354 		vb->state = VB2_BUF_STATE_DEQUEUED;
355 		vb->vb2_queue = q;
356 		vb->num_planes = num_planes;
357 		vb->index = q->num_buffers + buffer;
358 		vb->type = q->type;
359 		vb->memory = memory;
360 		for (plane = 0; plane < num_planes; ++plane) {
361 			vb->planes[plane].length = plane_sizes[plane];
362 			vb->planes[plane].min_length = plane_sizes[plane];
363 		}
364 		call_void_bufop(q, init_buffer, vb);
365 
366 		q->bufs[vb->index] = vb;
367 
368 		/* Allocate video buffer memory for the MMAP type */
369 		if (memory == VB2_MEMORY_MMAP) {
370 			ret = __vb2_buf_mem_alloc(vb);
371 			if (ret) {
372 				dprintk(1, "failed allocating memory for buffer %d\n",
373 					buffer);
374 				q->bufs[vb->index] = NULL;
375 				kfree(vb);
376 				break;
377 			}
378 			__setup_offsets(vb);
379 			/*
380 			 * Call the driver-provided buffer initialization
381 			 * callback, if given. An error in initialization
382 			 * results in queue setup failure.
383 			 */
384 			ret = call_vb_qop(vb, buf_init, vb);
385 			if (ret) {
386 				dprintk(1, "buffer %d %p initialization failed\n",
387 					buffer, vb);
388 				__vb2_buf_mem_free(vb);
389 				q->bufs[vb->index] = NULL;
390 				kfree(vb);
391 				break;
392 			}
393 		}
394 	}
395 
396 	dprintk(3, "allocated %d buffers, %d plane(s) each\n",
397 		buffer, num_planes);
398 
399 	return buffer;
400 }
401 
402 /*
403  * __vb2_free_mem() - release all video buffer memory for a given queue
404  */
405 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
406 {
407 	unsigned int buffer;
408 	struct vb2_buffer *vb;
409 
410 	for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
411 	     ++buffer) {
412 		vb = q->bufs[buffer];
413 		if (!vb)
414 			continue;
415 
416 		/* Free MMAP buffers or release USERPTR buffers */
417 		if (q->memory == VB2_MEMORY_MMAP)
418 			__vb2_buf_mem_free(vb);
419 		else if (q->memory == VB2_MEMORY_DMABUF)
420 			__vb2_buf_dmabuf_put(vb);
421 		else
422 			__vb2_buf_userptr_put(vb);
423 	}
424 }
425 
426 /*
427  * __vb2_queue_free() - free buffers at the end of the queue - video memory and
428  * related information, if no buffers are left return the queue to an
429  * uninitialized state. Might be called even if the queue has already been freed.
430  */
431 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
432 {
433 	unsigned int buffer;
434 
435 	/*
436 	 * Sanity check: when preparing a buffer the queue lock is released for
437 	 * a short while (see __buf_prepare for the details), which would allow
438 	 * a race with a reqbufs which can call this function. Removing the
439 	 * buffers from underneath __buf_prepare is obviously a bad idea, so we
440 	 * check if any of the buffers is in the state PREPARING, and if so we
441 	 * just return -EAGAIN.
442 	 */
443 	for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
444 	     ++buffer) {
445 		if (q->bufs[buffer] == NULL)
446 			continue;
447 		if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
448 			dprintk(1, "preparing buffers, cannot free\n");
449 			return -EAGAIN;
450 		}
451 	}
452 
453 	/* Call driver-provided cleanup function for each buffer, if provided */
454 	for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
455 	     ++buffer) {
456 		struct vb2_buffer *vb = q->bufs[buffer];
457 
458 		if (vb && vb->planes[0].mem_priv)
459 			call_void_vb_qop(vb, buf_cleanup, vb);
460 	}
461 
462 	/* Release video buffer memory */
463 	__vb2_free_mem(q, buffers);
464 
465 #ifdef CONFIG_VIDEO_ADV_DEBUG
466 	/*
467 	 * Check that all the calls were balances during the life-time of this
468 	 * queue. If not (or if the debug level is 1 or up), then dump the
469 	 * counters to the kernel log.
470 	 */
471 	if (q->num_buffers) {
472 		bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
473 				  q->cnt_wait_prepare != q->cnt_wait_finish;
474 
475 		if (unbalanced || debug) {
476 			pr_info("counters for queue %p:%s\n", q,
477 				unbalanced ? " UNBALANCED!" : "");
478 			pr_info("     setup: %u start_streaming: %u stop_streaming: %u\n",
479 				q->cnt_queue_setup, q->cnt_start_streaming,
480 				q->cnt_stop_streaming);
481 			pr_info("     wait_prepare: %u wait_finish: %u\n",
482 				q->cnt_wait_prepare, q->cnt_wait_finish);
483 		}
484 		q->cnt_queue_setup = 0;
485 		q->cnt_wait_prepare = 0;
486 		q->cnt_wait_finish = 0;
487 		q->cnt_start_streaming = 0;
488 		q->cnt_stop_streaming = 0;
489 	}
490 	for (buffer = 0; buffer < q->num_buffers; ++buffer) {
491 		struct vb2_buffer *vb = q->bufs[buffer];
492 		bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
493 				  vb->cnt_mem_prepare != vb->cnt_mem_finish ||
494 				  vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
495 				  vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
496 				  vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
497 				  vb->cnt_buf_queue != vb->cnt_buf_done ||
498 				  vb->cnt_buf_prepare != vb->cnt_buf_finish ||
499 				  vb->cnt_buf_init != vb->cnt_buf_cleanup;
500 
501 		if (unbalanced || debug) {
502 			pr_info("   counters for queue %p, buffer %d:%s\n",
503 				q, buffer, unbalanced ? " UNBALANCED!" : "");
504 			pr_info("     buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
505 				vb->cnt_buf_init, vb->cnt_buf_cleanup,
506 				vb->cnt_buf_prepare, vb->cnt_buf_finish);
507 			pr_info("     buf_out_validate: %u buf_queue: %u buf_done: %u buf_request_complete: %u\n",
508 				vb->cnt_buf_out_validate, vb->cnt_buf_queue,
509 				vb->cnt_buf_done, vb->cnt_buf_request_complete);
510 			pr_info("     alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
511 				vb->cnt_mem_alloc, vb->cnt_mem_put,
512 				vb->cnt_mem_prepare, vb->cnt_mem_finish,
513 				vb->cnt_mem_mmap);
514 			pr_info("     get_userptr: %u put_userptr: %u\n",
515 				vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
516 			pr_info("     attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
517 				vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
518 				vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
519 			pr_info("     get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
520 				vb->cnt_mem_get_dmabuf,
521 				vb->cnt_mem_num_users,
522 				vb->cnt_mem_vaddr,
523 				vb->cnt_mem_cookie);
524 		}
525 	}
526 #endif
527 
528 	/* Free videobuf buffers */
529 	for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
530 	     ++buffer) {
531 		kfree(q->bufs[buffer]);
532 		q->bufs[buffer] = NULL;
533 	}
534 
535 	q->num_buffers -= buffers;
536 	if (!q->num_buffers) {
537 		q->memory = VB2_MEMORY_UNKNOWN;
538 		INIT_LIST_HEAD(&q->queued_list);
539 	}
540 	return 0;
541 }
542 
543 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
544 {
545 	unsigned int plane;
546 	for (plane = 0; plane < vb->num_planes; ++plane) {
547 		void *mem_priv = vb->planes[plane].mem_priv;
548 		/*
549 		 * If num_users() has not been provided, call_memop
550 		 * will return 0, apparently nobody cares about this
551 		 * case anyway. If num_users() returns more than 1,
552 		 * we are not the only user of the plane's memory.
553 		 */
554 		if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
555 			return true;
556 	}
557 	return false;
558 }
559 EXPORT_SYMBOL(vb2_buffer_in_use);
560 
561 /*
562  * __buffers_in_use() - return true if any buffers on the queue are in use and
563  * the queue cannot be freed (by the means of REQBUFS(0)) call
564  */
565 static bool __buffers_in_use(struct vb2_queue *q)
566 {
567 	unsigned int buffer;
568 	for (buffer = 0; buffer < q->num_buffers; ++buffer) {
569 		if (vb2_buffer_in_use(q, q->bufs[buffer]))
570 			return true;
571 	}
572 	return false;
573 }
574 
575 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
576 {
577 	call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
578 }
579 EXPORT_SYMBOL_GPL(vb2_core_querybuf);
580 
581 /*
582  * __verify_userptr_ops() - verify that all memory operations required for
583  * USERPTR queue type have been provided
584  */
585 static int __verify_userptr_ops(struct vb2_queue *q)
586 {
587 	if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
588 	    !q->mem_ops->put_userptr)
589 		return -EINVAL;
590 
591 	return 0;
592 }
593 
594 /*
595  * __verify_mmap_ops() - verify that all memory operations required for
596  * MMAP queue type have been provided
597  */
598 static int __verify_mmap_ops(struct vb2_queue *q)
599 {
600 	if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
601 	    !q->mem_ops->put || !q->mem_ops->mmap)
602 		return -EINVAL;
603 
604 	return 0;
605 }
606 
607 /*
608  * __verify_dmabuf_ops() - verify that all memory operations required for
609  * DMABUF queue type have been provided
610  */
611 static int __verify_dmabuf_ops(struct vb2_queue *q)
612 {
613 	if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
614 	    !q->mem_ops->detach_dmabuf  || !q->mem_ops->map_dmabuf ||
615 	    !q->mem_ops->unmap_dmabuf)
616 		return -EINVAL;
617 
618 	return 0;
619 }
620 
621 int vb2_verify_memory_type(struct vb2_queue *q,
622 		enum vb2_memory memory, unsigned int type)
623 {
624 	if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR &&
625 	    memory != VB2_MEMORY_DMABUF) {
626 		dprintk(1, "unsupported memory type\n");
627 		return -EINVAL;
628 	}
629 
630 	if (type != q->type) {
631 		dprintk(1, "requested type is incorrect\n");
632 		return -EINVAL;
633 	}
634 
635 	/*
636 	 * Make sure all the required memory ops for given memory type
637 	 * are available.
638 	 */
639 	if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) {
640 		dprintk(1, "MMAP for current setup unsupported\n");
641 		return -EINVAL;
642 	}
643 
644 	if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
645 		dprintk(1, "USERPTR for current setup unsupported\n");
646 		return -EINVAL;
647 	}
648 
649 	if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
650 		dprintk(1, "DMABUF for current setup unsupported\n");
651 		return -EINVAL;
652 	}
653 
654 	/*
655 	 * Place the busy tests at the end: -EBUSY can be ignored when
656 	 * create_bufs is called with count == 0, but count == 0 should still
657 	 * do the memory and type validation.
658 	 */
659 	if (vb2_fileio_is_active(q)) {
660 		dprintk(1, "file io in progress\n");
661 		return -EBUSY;
662 	}
663 	return 0;
664 }
665 EXPORT_SYMBOL(vb2_verify_memory_type);
666 
667 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
668 		unsigned int *count)
669 {
670 	unsigned int num_buffers, allocated_buffers, num_planes = 0;
671 	unsigned plane_sizes[VB2_MAX_PLANES] = { };
672 	unsigned int i;
673 	int ret;
674 
675 	if (q->streaming) {
676 		dprintk(1, "streaming active\n");
677 		return -EBUSY;
678 	}
679 
680 	if (q->waiting_in_dqbuf && *count) {
681 		dprintk(1, "another dup()ped fd is waiting for a buffer\n");
682 		return -EBUSY;
683 	}
684 
685 	if (*count == 0 || q->num_buffers != 0 ||
686 	    (q->memory != VB2_MEMORY_UNKNOWN && q->memory != memory)) {
687 		/*
688 		 * We already have buffers allocated, so first check if they
689 		 * are not in use and can be freed.
690 		 */
691 		mutex_lock(&q->mmap_lock);
692 		if (debug && q->memory == VB2_MEMORY_MMAP &&
693 		    __buffers_in_use(q))
694 			dprintk(1, "memory in use, orphaning buffers\n");
695 
696 		/*
697 		 * Call queue_cancel to clean up any buffers in the
698 		 * QUEUED state which is possible if buffers were prepared or
699 		 * queued without ever calling STREAMON.
700 		 */
701 		__vb2_queue_cancel(q);
702 		ret = __vb2_queue_free(q, q->num_buffers);
703 		mutex_unlock(&q->mmap_lock);
704 		if (ret)
705 			return ret;
706 
707 		/*
708 		 * In case of REQBUFS(0) return immediately without calling
709 		 * driver's queue_setup() callback and allocating resources.
710 		 */
711 		if (*count == 0)
712 			return 0;
713 	}
714 
715 	/*
716 	 * Make sure the requested values and current defaults are sane.
717 	 */
718 	WARN_ON(q->min_buffers_needed > VB2_MAX_FRAME);
719 	num_buffers = max_t(unsigned int, *count, q->min_buffers_needed);
720 	num_buffers = min_t(unsigned int, num_buffers, VB2_MAX_FRAME);
721 	memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
722 	q->memory = memory;
723 
724 	/*
725 	 * Ask the driver how many buffers and planes per buffer it requires.
726 	 * Driver also sets the size and allocator context for each plane.
727 	 */
728 	ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
729 		       plane_sizes, q->alloc_devs);
730 	if (ret)
731 		return ret;
732 
733 	/* Check that driver has set sane values */
734 	if (WARN_ON(!num_planes))
735 		return -EINVAL;
736 
737 	for (i = 0; i < num_planes; i++)
738 		if (WARN_ON(!plane_sizes[i]))
739 			return -EINVAL;
740 
741 	/* Finally, allocate buffers and video memory */
742 	allocated_buffers =
743 		__vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
744 	if (allocated_buffers == 0) {
745 		dprintk(1, "memory allocation failed\n");
746 		return -ENOMEM;
747 	}
748 
749 	/*
750 	 * There is no point in continuing if we can't allocate the minimum
751 	 * number of buffers needed by this vb2_queue.
752 	 */
753 	if (allocated_buffers < q->min_buffers_needed)
754 		ret = -ENOMEM;
755 
756 	/*
757 	 * Check if driver can handle the allocated number of buffers.
758 	 */
759 	if (!ret && allocated_buffers < num_buffers) {
760 		num_buffers = allocated_buffers;
761 		/*
762 		 * num_planes is set by the previous queue_setup(), but since it
763 		 * signals to queue_setup() whether it is called from create_bufs()
764 		 * vs reqbufs() we zero it here to signal that queue_setup() is
765 		 * called for the reqbufs() case.
766 		 */
767 		num_planes = 0;
768 
769 		ret = call_qop(q, queue_setup, q, &num_buffers,
770 			       &num_planes, plane_sizes, q->alloc_devs);
771 
772 		if (!ret && allocated_buffers < num_buffers)
773 			ret = -ENOMEM;
774 
775 		/*
776 		 * Either the driver has accepted a smaller number of buffers,
777 		 * or .queue_setup() returned an error
778 		 */
779 	}
780 
781 	mutex_lock(&q->mmap_lock);
782 	q->num_buffers = allocated_buffers;
783 
784 	if (ret < 0) {
785 		/*
786 		 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
787 		 * from q->num_buffers.
788 		 */
789 		__vb2_queue_free(q, allocated_buffers);
790 		mutex_unlock(&q->mmap_lock);
791 		return ret;
792 	}
793 	mutex_unlock(&q->mmap_lock);
794 
795 	/*
796 	 * Return the number of successfully allocated buffers
797 	 * to the userspace.
798 	 */
799 	*count = allocated_buffers;
800 	q->waiting_for_buffers = !q->is_output;
801 
802 	return 0;
803 }
804 EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
805 
806 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
807 		unsigned int *count, unsigned requested_planes,
808 		const unsigned requested_sizes[])
809 {
810 	unsigned int num_planes = 0, num_buffers, allocated_buffers;
811 	unsigned plane_sizes[VB2_MAX_PLANES] = { };
812 	int ret;
813 
814 	if (q->num_buffers == VB2_MAX_FRAME) {
815 		dprintk(1, "maximum number of buffers already allocated\n");
816 		return -ENOBUFS;
817 	}
818 
819 	if (!q->num_buffers) {
820 		if (q->waiting_in_dqbuf && *count) {
821 			dprintk(1, "another dup()ped fd is waiting for a buffer\n");
822 			return -EBUSY;
823 		}
824 		memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
825 		q->memory = memory;
826 		q->waiting_for_buffers = !q->is_output;
827 	} else if (q->memory != memory) {
828 		dprintk(1, "memory model mismatch\n");
829 		return -EINVAL;
830 	}
831 
832 	num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
833 
834 	if (requested_planes && requested_sizes) {
835 		num_planes = requested_planes;
836 		memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes));
837 	}
838 
839 	/*
840 	 * Ask the driver, whether the requested number of buffers, planes per
841 	 * buffer and their sizes are acceptable
842 	 */
843 	ret = call_qop(q, queue_setup, q, &num_buffers,
844 		       &num_planes, plane_sizes, q->alloc_devs);
845 	if (ret)
846 		return ret;
847 
848 	/* Finally, allocate buffers and video memory */
849 	allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
850 				num_planes, plane_sizes);
851 	if (allocated_buffers == 0) {
852 		dprintk(1, "memory allocation failed\n");
853 		return -ENOMEM;
854 	}
855 
856 	/*
857 	 * Check if driver can handle the so far allocated number of buffers.
858 	 */
859 	if (allocated_buffers < num_buffers) {
860 		num_buffers = allocated_buffers;
861 
862 		/*
863 		 * q->num_buffers contains the total number of buffers, that the
864 		 * queue driver has set up
865 		 */
866 		ret = call_qop(q, queue_setup, q, &num_buffers,
867 			       &num_planes, plane_sizes, q->alloc_devs);
868 
869 		if (!ret && allocated_buffers < num_buffers)
870 			ret = -ENOMEM;
871 
872 		/*
873 		 * Either the driver has accepted a smaller number of buffers,
874 		 * or .queue_setup() returned an error
875 		 */
876 	}
877 
878 	mutex_lock(&q->mmap_lock);
879 	q->num_buffers += allocated_buffers;
880 
881 	if (ret < 0) {
882 		/*
883 		 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
884 		 * from q->num_buffers.
885 		 */
886 		__vb2_queue_free(q, allocated_buffers);
887 		mutex_unlock(&q->mmap_lock);
888 		return -ENOMEM;
889 	}
890 	mutex_unlock(&q->mmap_lock);
891 
892 	/*
893 	 * Return the number of successfully allocated buffers
894 	 * to the userspace.
895 	 */
896 	*count = allocated_buffers;
897 
898 	return 0;
899 }
900 EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
901 
902 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
903 {
904 	if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
905 		return NULL;
906 
907 	return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
908 
909 }
910 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
911 
912 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
913 {
914 	if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
915 		return NULL;
916 
917 	return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
918 }
919 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
920 
921 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
922 {
923 	struct vb2_queue *q = vb->vb2_queue;
924 	unsigned long flags;
925 	unsigned int plane;
926 
927 	if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
928 		return;
929 
930 	if (WARN_ON(state != VB2_BUF_STATE_DONE &&
931 		    state != VB2_BUF_STATE_ERROR &&
932 		    state != VB2_BUF_STATE_QUEUED))
933 		state = VB2_BUF_STATE_ERROR;
934 
935 #ifdef CONFIG_VIDEO_ADV_DEBUG
936 	/*
937 	 * Although this is not a callback, it still does have to balance
938 	 * with the buf_queue op. So update this counter manually.
939 	 */
940 	vb->cnt_buf_done++;
941 #endif
942 	dprintk(4, "done processing on buffer %d, state: %d\n",
943 			vb->index, state);
944 
945 	if (state != VB2_BUF_STATE_QUEUED) {
946 		/* sync buffers */
947 		for (plane = 0; plane < vb->num_planes; ++plane)
948 			call_void_memop(vb, finish, vb->planes[plane].mem_priv);
949 		vb->synced = 0;
950 	}
951 
952 	spin_lock_irqsave(&q->done_lock, flags);
953 	if (state == VB2_BUF_STATE_QUEUED) {
954 		vb->state = VB2_BUF_STATE_QUEUED;
955 	} else {
956 		/* Add the buffer to the done buffers list */
957 		list_add_tail(&vb->done_entry, &q->done_list);
958 		vb->state = state;
959 	}
960 	atomic_dec(&q->owned_by_drv_count);
961 
962 	if (state != VB2_BUF_STATE_QUEUED && vb->req_obj.req) {
963 		media_request_object_unbind(&vb->req_obj);
964 		media_request_object_put(&vb->req_obj);
965 	}
966 
967 	spin_unlock_irqrestore(&q->done_lock, flags);
968 
969 	trace_vb2_buf_done(q, vb);
970 
971 	switch (state) {
972 	case VB2_BUF_STATE_QUEUED:
973 		return;
974 	default:
975 		/* Inform any processes that may be waiting for buffers */
976 		wake_up(&q->done_wq);
977 		break;
978 	}
979 }
980 EXPORT_SYMBOL_GPL(vb2_buffer_done);
981 
982 void vb2_discard_done(struct vb2_queue *q)
983 {
984 	struct vb2_buffer *vb;
985 	unsigned long flags;
986 
987 	spin_lock_irqsave(&q->done_lock, flags);
988 	list_for_each_entry(vb, &q->done_list, done_entry)
989 		vb->state = VB2_BUF_STATE_ERROR;
990 	spin_unlock_irqrestore(&q->done_lock, flags);
991 }
992 EXPORT_SYMBOL_GPL(vb2_discard_done);
993 
994 /*
995  * __prepare_mmap() - prepare an MMAP buffer
996  */
997 static int __prepare_mmap(struct vb2_buffer *vb)
998 {
999 	int ret = 0;
1000 
1001 	ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1002 			 vb, vb->planes);
1003 	return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
1004 }
1005 
1006 /*
1007  * __prepare_userptr() - prepare a USERPTR buffer
1008  */
1009 static int __prepare_userptr(struct vb2_buffer *vb)
1010 {
1011 	struct vb2_plane planes[VB2_MAX_PLANES];
1012 	struct vb2_queue *q = vb->vb2_queue;
1013 	void *mem_priv;
1014 	unsigned int plane;
1015 	int ret = 0;
1016 	bool reacquired = vb->planes[0].mem_priv == NULL;
1017 
1018 	memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1019 	/* Copy relevant information provided by the userspace */
1020 	ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1021 			 vb, planes);
1022 	if (ret)
1023 		return ret;
1024 
1025 	for (plane = 0; plane < vb->num_planes; ++plane) {
1026 		/* Skip the plane if already verified */
1027 		if (vb->planes[plane].m.userptr &&
1028 			vb->planes[plane].m.userptr == planes[plane].m.userptr
1029 			&& vb->planes[plane].length == planes[plane].length)
1030 			continue;
1031 
1032 		dprintk(3, "userspace address for plane %d changed, reacquiring memory\n",
1033 			plane);
1034 
1035 		/* Check if the provided plane buffer is large enough */
1036 		if (planes[plane].length < vb->planes[plane].min_length) {
1037 			dprintk(1, "provided buffer size %u is less than setup size %u for plane %d\n",
1038 						planes[plane].length,
1039 						vb->planes[plane].min_length,
1040 						plane);
1041 			ret = -EINVAL;
1042 			goto err;
1043 		}
1044 
1045 		/* Release previously acquired memory if present */
1046 		if (vb->planes[plane].mem_priv) {
1047 			if (!reacquired) {
1048 				reacquired = true;
1049 				vb->copied_timestamp = 0;
1050 				call_void_vb_qop(vb, buf_cleanup, vb);
1051 			}
1052 			call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1053 		}
1054 
1055 		vb->planes[plane].mem_priv = NULL;
1056 		vb->planes[plane].bytesused = 0;
1057 		vb->planes[plane].length = 0;
1058 		vb->planes[plane].m.userptr = 0;
1059 		vb->planes[plane].data_offset = 0;
1060 
1061 		/* Acquire each plane's memory */
1062 		mem_priv = call_ptr_memop(vb, get_userptr,
1063 				q->alloc_devs[plane] ? : q->dev,
1064 				planes[plane].m.userptr,
1065 				planes[plane].length, q->dma_dir);
1066 		if (IS_ERR(mem_priv)) {
1067 			dprintk(1, "failed acquiring userspace memory for plane %d\n",
1068 				plane);
1069 			ret = PTR_ERR(mem_priv);
1070 			goto err;
1071 		}
1072 		vb->planes[plane].mem_priv = mem_priv;
1073 	}
1074 
1075 	/*
1076 	 * Now that everything is in order, copy relevant information
1077 	 * provided by userspace.
1078 	 */
1079 	for (plane = 0; plane < vb->num_planes; ++plane) {
1080 		vb->planes[plane].bytesused = planes[plane].bytesused;
1081 		vb->planes[plane].length = planes[plane].length;
1082 		vb->planes[plane].m.userptr = planes[plane].m.userptr;
1083 		vb->planes[plane].data_offset = planes[plane].data_offset;
1084 	}
1085 
1086 	if (reacquired) {
1087 		/*
1088 		 * One or more planes changed, so we must call buf_init to do
1089 		 * the driver-specific initialization on the newly acquired
1090 		 * buffer, if provided.
1091 		 */
1092 		ret = call_vb_qop(vb, buf_init, vb);
1093 		if (ret) {
1094 			dprintk(1, "buffer initialization failed\n");
1095 			goto err;
1096 		}
1097 	}
1098 
1099 	ret = call_vb_qop(vb, buf_prepare, vb);
1100 	if (ret) {
1101 		dprintk(1, "buffer preparation failed\n");
1102 		call_void_vb_qop(vb, buf_cleanup, vb);
1103 		goto err;
1104 	}
1105 
1106 	return 0;
1107 err:
1108 	/* In case of errors, release planes that were already acquired */
1109 	for (plane = 0; plane < vb->num_planes; ++plane) {
1110 		if (vb->planes[plane].mem_priv)
1111 			call_void_memop(vb, put_userptr,
1112 				vb->planes[plane].mem_priv);
1113 		vb->planes[plane].mem_priv = NULL;
1114 		vb->planes[plane].m.userptr = 0;
1115 		vb->planes[plane].length = 0;
1116 	}
1117 
1118 	return ret;
1119 }
1120 
1121 /*
1122  * __prepare_dmabuf() - prepare a DMABUF buffer
1123  */
1124 static int __prepare_dmabuf(struct vb2_buffer *vb)
1125 {
1126 	struct vb2_plane planes[VB2_MAX_PLANES];
1127 	struct vb2_queue *q = vb->vb2_queue;
1128 	void *mem_priv;
1129 	unsigned int plane;
1130 	int ret = 0;
1131 	bool reacquired = vb->planes[0].mem_priv == NULL;
1132 
1133 	memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1134 	/* Copy relevant information provided by the userspace */
1135 	ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1136 			 vb, planes);
1137 	if (ret)
1138 		return ret;
1139 
1140 	for (plane = 0; plane < vb->num_planes; ++plane) {
1141 		struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1142 
1143 		if (IS_ERR_OR_NULL(dbuf)) {
1144 			dprintk(1, "invalid dmabuf fd for plane %d\n",
1145 				plane);
1146 			ret = -EINVAL;
1147 			goto err;
1148 		}
1149 
1150 		/* use DMABUF size if length is not provided */
1151 		if (planes[plane].length == 0)
1152 			planes[plane].length = dbuf->size;
1153 
1154 		if (planes[plane].length < vb->planes[plane].min_length) {
1155 			dprintk(1, "invalid dmabuf length %u for plane %d, minimum length %u\n",
1156 				planes[plane].length, plane,
1157 				vb->planes[plane].min_length);
1158 			dma_buf_put(dbuf);
1159 			ret = -EINVAL;
1160 			goto err;
1161 		}
1162 
1163 		/* Skip the plane if already verified */
1164 		if (dbuf == vb->planes[plane].dbuf &&
1165 			vb->planes[plane].length == planes[plane].length) {
1166 			dma_buf_put(dbuf);
1167 			continue;
1168 		}
1169 
1170 		dprintk(3, "buffer for plane %d changed\n", plane);
1171 
1172 		if (!reacquired) {
1173 			reacquired = true;
1174 			vb->copied_timestamp = 0;
1175 			call_void_vb_qop(vb, buf_cleanup, vb);
1176 		}
1177 
1178 		/* Release previously acquired memory if present */
1179 		__vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1180 		vb->planes[plane].bytesused = 0;
1181 		vb->planes[plane].length = 0;
1182 		vb->planes[plane].m.fd = 0;
1183 		vb->planes[plane].data_offset = 0;
1184 
1185 		/* Acquire each plane's memory */
1186 		mem_priv = call_ptr_memop(vb, attach_dmabuf,
1187 				q->alloc_devs[plane] ? : q->dev,
1188 				dbuf, planes[plane].length, q->dma_dir);
1189 		if (IS_ERR(mem_priv)) {
1190 			dprintk(1, "failed to attach dmabuf\n");
1191 			ret = PTR_ERR(mem_priv);
1192 			dma_buf_put(dbuf);
1193 			goto err;
1194 		}
1195 
1196 		vb->planes[plane].dbuf = dbuf;
1197 		vb->planes[plane].mem_priv = mem_priv;
1198 	}
1199 
1200 	/*
1201 	 * This pins the buffer(s) with dma_buf_map_attachment()). It's done
1202 	 * here instead just before the DMA, while queueing the buffer(s) so
1203 	 * userspace knows sooner rather than later if the dma-buf map fails.
1204 	 */
1205 	for (plane = 0; plane < vb->num_planes; ++plane) {
1206 		if (vb->planes[plane].dbuf_mapped)
1207 			continue;
1208 
1209 		ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1210 		if (ret) {
1211 			dprintk(1, "failed to map dmabuf for plane %d\n",
1212 				plane);
1213 			goto err;
1214 		}
1215 		vb->planes[plane].dbuf_mapped = 1;
1216 	}
1217 
1218 	/*
1219 	 * Now that everything is in order, copy relevant information
1220 	 * provided by userspace.
1221 	 */
1222 	for (plane = 0; plane < vb->num_planes; ++plane) {
1223 		vb->planes[plane].bytesused = planes[plane].bytesused;
1224 		vb->planes[plane].length = planes[plane].length;
1225 		vb->planes[plane].m.fd = planes[plane].m.fd;
1226 		vb->planes[plane].data_offset = planes[plane].data_offset;
1227 	}
1228 
1229 	if (reacquired) {
1230 		/*
1231 		 * Call driver-specific initialization on the newly acquired buffer,
1232 		 * if provided.
1233 		 */
1234 		ret = call_vb_qop(vb, buf_init, vb);
1235 		if (ret) {
1236 			dprintk(1, "buffer initialization failed\n");
1237 			goto err;
1238 		}
1239 	}
1240 
1241 	ret = call_vb_qop(vb, buf_prepare, vb);
1242 	if (ret) {
1243 		dprintk(1, "buffer preparation failed\n");
1244 		call_void_vb_qop(vb, buf_cleanup, vb);
1245 		goto err;
1246 	}
1247 
1248 	return 0;
1249 err:
1250 	/* In case of errors, release planes that were already acquired */
1251 	__vb2_buf_dmabuf_put(vb);
1252 
1253 	return ret;
1254 }
1255 
1256 /*
1257  * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1258  */
1259 static void __enqueue_in_driver(struct vb2_buffer *vb)
1260 {
1261 	struct vb2_queue *q = vb->vb2_queue;
1262 
1263 	vb->state = VB2_BUF_STATE_ACTIVE;
1264 	atomic_inc(&q->owned_by_drv_count);
1265 
1266 	trace_vb2_buf_queue(q, vb);
1267 
1268 	call_void_vb_qop(vb, buf_queue, vb);
1269 }
1270 
1271 static int __buf_prepare(struct vb2_buffer *vb)
1272 {
1273 	struct vb2_queue *q = vb->vb2_queue;
1274 	enum vb2_buffer_state orig_state = vb->state;
1275 	unsigned int plane;
1276 	int ret;
1277 
1278 	if (q->error) {
1279 		dprintk(1, "fatal error occurred on queue\n");
1280 		return -EIO;
1281 	}
1282 
1283 	if (vb->prepared)
1284 		return 0;
1285 	WARN_ON(vb->synced);
1286 
1287 	if (q->is_output) {
1288 		ret = call_vb_qop(vb, buf_out_validate, vb);
1289 		if (ret) {
1290 			dprintk(1, "buffer validation failed\n");
1291 			return ret;
1292 		}
1293 	}
1294 
1295 	vb->state = VB2_BUF_STATE_PREPARING;
1296 
1297 	switch (q->memory) {
1298 	case VB2_MEMORY_MMAP:
1299 		ret = __prepare_mmap(vb);
1300 		break;
1301 	case VB2_MEMORY_USERPTR:
1302 		ret = __prepare_userptr(vb);
1303 		break;
1304 	case VB2_MEMORY_DMABUF:
1305 		ret = __prepare_dmabuf(vb);
1306 		break;
1307 	default:
1308 		WARN(1, "Invalid queue type\n");
1309 		ret = -EINVAL;
1310 		break;
1311 	}
1312 
1313 	if (ret) {
1314 		dprintk(1, "buffer preparation failed: %d\n", ret);
1315 		vb->state = orig_state;
1316 		return ret;
1317 	}
1318 
1319 	/* sync buffers */
1320 	for (plane = 0; plane < vb->num_planes; ++plane)
1321 		call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
1322 
1323 	vb->synced = 1;
1324 	vb->prepared = 1;
1325 	vb->state = orig_state;
1326 
1327 	return 0;
1328 }
1329 
1330 static int vb2_req_prepare(struct media_request_object *obj)
1331 {
1332 	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1333 	int ret;
1334 
1335 	if (WARN_ON(vb->state != VB2_BUF_STATE_IN_REQUEST))
1336 		return -EINVAL;
1337 
1338 	mutex_lock(vb->vb2_queue->lock);
1339 	ret = __buf_prepare(vb);
1340 	mutex_unlock(vb->vb2_queue->lock);
1341 	return ret;
1342 }
1343 
1344 static void __vb2_dqbuf(struct vb2_buffer *vb);
1345 
1346 static void vb2_req_unprepare(struct media_request_object *obj)
1347 {
1348 	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1349 
1350 	mutex_lock(vb->vb2_queue->lock);
1351 	__vb2_dqbuf(vb);
1352 	vb->state = VB2_BUF_STATE_IN_REQUEST;
1353 	mutex_unlock(vb->vb2_queue->lock);
1354 	WARN_ON(!vb->req_obj.req);
1355 }
1356 
1357 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
1358 		  struct media_request *req);
1359 
1360 static void vb2_req_queue(struct media_request_object *obj)
1361 {
1362 	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1363 
1364 	mutex_lock(vb->vb2_queue->lock);
1365 	vb2_core_qbuf(vb->vb2_queue, vb->index, NULL, NULL);
1366 	mutex_unlock(vb->vb2_queue->lock);
1367 }
1368 
1369 static void vb2_req_unbind(struct media_request_object *obj)
1370 {
1371 	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1372 
1373 	if (vb->state == VB2_BUF_STATE_IN_REQUEST)
1374 		call_void_bufop(vb->vb2_queue, init_buffer, vb);
1375 }
1376 
1377 static void vb2_req_release(struct media_request_object *obj)
1378 {
1379 	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1380 
1381 	if (vb->state == VB2_BUF_STATE_IN_REQUEST) {
1382 		vb->state = VB2_BUF_STATE_DEQUEUED;
1383 		if (vb->request)
1384 			media_request_put(vb->request);
1385 		vb->request = NULL;
1386 	}
1387 }
1388 
1389 static const struct media_request_object_ops vb2_core_req_ops = {
1390 	.prepare = vb2_req_prepare,
1391 	.unprepare = vb2_req_unprepare,
1392 	.queue = vb2_req_queue,
1393 	.unbind = vb2_req_unbind,
1394 	.release = vb2_req_release,
1395 };
1396 
1397 bool vb2_request_object_is_buffer(struct media_request_object *obj)
1398 {
1399 	return obj->ops == &vb2_core_req_ops;
1400 }
1401 EXPORT_SYMBOL_GPL(vb2_request_object_is_buffer);
1402 
1403 unsigned int vb2_request_buffer_cnt(struct media_request *req)
1404 {
1405 	struct media_request_object *obj;
1406 	unsigned long flags;
1407 	unsigned int buffer_cnt = 0;
1408 
1409 	spin_lock_irqsave(&req->lock, flags);
1410 	list_for_each_entry(obj, &req->objects, list)
1411 		if (vb2_request_object_is_buffer(obj))
1412 			buffer_cnt++;
1413 	spin_unlock_irqrestore(&req->lock, flags);
1414 
1415 	return buffer_cnt;
1416 }
1417 EXPORT_SYMBOL_GPL(vb2_request_buffer_cnt);
1418 
1419 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
1420 {
1421 	struct vb2_buffer *vb;
1422 	int ret;
1423 
1424 	vb = q->bufs[index];
1425 	if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1426 		dprintk(1, "invalid buffer state %d\n",
1427 			vb->state);
1428 		return -EINVAL;
1429 	}
1430 	if (vb->prepared) {
1431 		dprintk(1, "buffer already prepared\n");
1432 		return -EINVAL;
1433 	}
1434 
1435 	ret = __buf_prepare(vb);
1436 	if (ret)
1437 		return ret;
1438 
1439 	/* Fill buffer information for the userspace */
1440 	call_void_bufop(q, fill_user_buffer, vb, pb);
1441 
1442 	dprintk(2, "prepare of buffer %d succeeded\n", vb->index);
1443 
1444 	return 0;
1445 }
1446 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
1447 
1448 /*
1449  * vb2_start_streaming() - Attempt to start streaming.
1450  * @q:		videobuf2 queue
1451  *
1452  * Attempt to start streaming. When this function is called there must be
1453  * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1454  * number of buffers required for the DMA engine to function). If the
1455  * @start_streaming op fails it is supposed to return all the driver-owned
1456  * buffers back to vb2 in state QUEUED. Check if that happened and if
1457  * not warn and reclaim them forcefully.
1458  */
1459 static int vb2_start_streaming(struct vb2_queue *q)
1460 {
1461 	struct vb2_buffer *vb;
1462 	int ret;
1463 
1464 	/*
1465 	 * If any buffers were queued before streamon,
1466 	 * we can now pass them to driver for processing.
1467 	 */
1468 	list_for_each_entry(vb, &q->queued_list, queued_entry)
1469 		__enqueue_in_driver(vb);
1470 
1471 	/* Tell the driver to start streaming */
1472 	q->start_streaming_called = 1;
1473 	ret = call_qop(q, start_streaming, q,
1474 		       atomic_read(&q->owned_by_drv_count));
1475 	if (!ret)
1476 		return 0;
1477 
1478 	q->start_streaming_called = 0;
1479 
1480 	dprintk(1, "driver refused to start streaming\n");
1481 	/*
1482 	 * If you see this warning, then the driver isn't cleaning up properly
1483 	 * after a failed start_streaming(). See the start_streaming()
1484 	 * documentation in videobuf2-core.h for more information how buffers
1485 	 * should be returned to vb2 in start_streaming().
1486 	 */
1487 	if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1488 		unsigned i;
1489 
1490 		/*
1491 		 * Forcefully reclaim buffers if the driver did not
1492 		 * correctly return them to vb2.
1493 		 */
1494 		for (i = 0; i < q->num_buffers; ++i) {
1495 			vb = q->bufs[i];
1496 			if (vb->state == VB2_BUF_STATE_ACTIVE)
1497 				vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1498 		}
1499 		/* Must be zero now */
1500 		WARN_ON(atomic_read(&q->owned_by_drv_count));
1501 	}
1502 	/*
1503 	 * If done_list is not empty, then start_streaming() didn't call
1504 	 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1505 	 * STATE_DONE.
1506 	 */
1507 	WARN_ON(!list_empty(&q->done_list));
1508 	return ret;
1509 }
1510 
1511 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
1512 		  struct media_request *req)
1513 {
1514 	struct vb2_buffer *vb;
1515 	int ret;
1516 
1517 	if (q->error) {
1518 		dprintk(1, "fatal error occurred on queue\n");
1519 		return -EIO;
1520 	}
1521 
1522 	vb = q->bufs[index];
1523 
1524 	if (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
1525 	    q->requires_requests) {
1526 		dprintk(1, "qbuf requires a request\n");
1527 		return -EBADR;
1528 	}
1529 
1530 	if ((req && q->uses_qbuf) ||
1531 	    (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
1532 	     q->uses_requests)) {
1533 		dprintk(1, "queue in wrong mode (qbuf vs requests)\n");
1534 		return -EBUSY;
1535 	}
1536 
1537 	if (req) {
1538 		int ret;
1539 
1540 		q->uses_requests = 1;
1541 		if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1542 			dprintk(1, "buffer %d not in dequeued state\n",
1543 				vb->index);
1544 			return -EINVAL;
1545 		}
1546 
1547 		if (q->is_output && !vb->prepared) {
1548 			ret = call_vb_qop(vb, buf_out_validate, vb);
1549 			if (ret) {
1550 				dprintk(1, "buffer validation failed\n");
1551 				return ret;
1552 			}
1553 		}
1554 
1555 		media_request_object_init(&vb->req_obj);
1556 
1557 		/* Make sure the request is in a safe state for updating. */
1558 		ret = media_request_lock_for_update(req);
1559 		if (ret)
1560 			return ret;
1561 		ret = media_request_object_bind(req, &vb2_core_req_ops,
1562 						q, true, &vb->req_obj);
1563 		media_request_unlock_for_update(req);
1564 		if (ret)
1565 			return ret;
1566 
1567 		vb->state = VB2_BUF_STATE_IN_REQUEST;
1568 
1569 		/*
1570 		 * Increment the refcount and store the request.
1571 		 * The request refcount is decremented again when the
1572 		 * buffer is dequeued. This is to prevent vb2_buffer_done()
1573 		 * from freeing the request from interrupt context, which can
1574 		 * happen if the application closed the request fd after
1575 		 * queueing the request.
1576 		 */
1577 		media_request_get(req);
1578 		vb->request = req;
1579 
1580 		/* Fill buffer information for the userspace */
1581 		if (pb) {
1582 			call_void_bufop(q, copy_timestamp, vb, pb);
1583 			call_void_bufop(q, fill_user_buffer, vb, pb);
1584 		}
1585 
1586 		dprintk(2, "qbuf of buffer %d succeeded\n", vb->index);
1587 		return 0;
1588 	}
1589 
1590 	if (vb->state != VB2_BUF_STATE_IN_REQUEST)
1591 		q->uses_qbuf = 1;
1592 
1593 	switch (vb->state) {
1594 	case VB2_BUF_STATE_DEQUEUED:
1595 	case VB2_BUF_STATE_IN_REQUEST:
1596 		if (!vb->prepared) {
1597 			ret = __buf_prepare(vb);
1598 			if (ret)
1599 				return ret;
1600 		}
1601 		break;
1602 	case VB2_BUF_STATE_PREPARING:
1603 		dprintk(1, "buffer still being prepared\n");
1604 		return -EINVAL;
1605 	default:
1606 		dprintk(1, "invalid buffer state %d\n", vb->state);
1607 		return -EINVAL;
1608 	}
1609 
1610 	/*
1611 	 * Add to the queued buffers list, a buffer will stay on it until
1612 	 * dequeued in dqbuf.
1613 	 */
1614 	list_add_tail(&vb->queued_entry, &q->queued_list);
1615 	q->queued_count++;
1616 	q->waiting_for_buffers = false;
1617 	vb->state = VB2_BUF_STATE_QUEUED;
1618 
1619 	if (pb)
1620 		call_void_bufop(q, copy_timestamp, vb, pb);
1621 
1622 	trace_vb2_qbuf(q, vb);
1623 
1624 	/*
1625 	 * If already streaming, give the buffer to driver for processing.
1626 	 * If not, the buffer will be given to driver on next streamon.
1627 	 */
1628 	if (q->start_streaming_called)
1629 		__enqueue_in_driver(vb);
1630 
1631 	/* Fill buffer information for the userspace */
1632 	if (pb)
1633 		call_void_bufop(q, fill_user_buffer, vb, pb);
1634 
1635 	/*
1636 	 * If streamon has been called, and we haven't yet called
1637 	 * start_streaming() since not enough buffers were queued, and
1638 	 * we now have reached the minimum number of queued buffers,
1639 	 * then we can finally call start_streaming().
1640 	 */
1641 	if (q->streaming && !q->start_streaming_called &&
1642 	    q->queued_count >= q->min_buffers_needed) {
1643 		ret = vb2_start_streaming(q);
1644 		if (ret)
1645 			return ret;
1646 	}
1647 
1648 	dprintk(2, "qbuf of buffer %d succeeded\n", vb->index);
1649 	return 0;
1650 }
1651 EXPORT_SYMBOL_GPL(vb2_core_qbuf);
1652 
1653 /*
1654  * __vb2_wait_for_done_vb() - wait for a buffer to become available
1655  * for dequeuing
1656  *
1657  * Will sleep if required for nonblocking == false.
1658  */
1659 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1660 {
1661 	/*
1662 	 * All operations on vb_done_list are performed under done_lock
1663 	 * spinlock protection. However, buffers may be removed from
1664 	 * it and returned to userspace only while holding both driver's
1665 	 * lock and the done_lock spinlock. Thus we can be sure that as
1666 	 * long as we hold the driver's lock, the list will remain not
1667 	 * empty if list_empty() check succeeds.
1668 	 */
1669 
1670 	for (;;) {
1671 		int ret;
1672 
1673 		if (q->waiting_in_dqbuf) {
1674 			dprintk(1, "another dup()ped fd is waiting for a buffer\n");
1675 			return -EBUSY;
1676 		}
1677 
1678 		if (!q->streaming) {
1679 			dprintk(1, "streaming off, will not wait for buffers\n");
1680 			return -EINVAL;
1681 		}
1682 
1683 		if (q->error) {
1684 			dprintk(1, "Queue in error state, will not wait for buffers\n");
1685 			return -EIO;
1686 		}
1687 
1688 		if (q->last_buffer_dequeued) {
1689 			dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
1690 			return -EPIPE;
1691 		}
1692 
1693 		if (!list_empty(&q->done_list)) {
1694 			/*
1695 			 * Found a buffer that we were waiting for.
1696 			 */
1697 			break;
1698 		}
1699 
1700 		if (nonblocking) {
1701 			dprintk(3, "nonblocking and no buffers to dequeue, will not wait\n");
1702 			return -EAGAIN;
1703 		}
1704 
1705 		q->waiting_in_dqbuf = 1;
1706 		/*
1707 		 * We are streaming and blocking, wait for another buffer to
1708 		 * become ready or for streamoff. Driver's lock is released to
1709 		 * allow streamoff or qbuf to be called while waiting.
1710 		 */
1711 		call_void_qop(q, wait_prepare, q);
1712 
1713 		/*
1714 		 * All locks have been released, it is safe to sleep now.
1715 		 */
1716 		dprintk(3, "will sleep waiting for buffers\n");
1717 		ret = wait_event_interruptible(q->done_wq,
1718 				!list_empty(&q->done_list) || !q->streaming ||
1719 				q->error);
1720 
1721 		/*
1722 		 * We need to reevaluate both conditions again after reacquiring
1723 		 * the locks or return an error if one occurred.
1724 		 */
1725 		call_void_qop(q, wait_finish, q);
1726 		q->waiting_in_dqbuf = 0;
1727 		if (ret) {
1728 			dprintk(1, "sleep was interrupted\n");
1729 			return ret;
1730 		}
1731 	}
1732 	return 0;
1733 }
1734 
1735 /*
1736  * __vb2_get_done_vb() - get a buffer ready for dequeuing
1737  *
1738  * Will sleep if required for nonblocking == false.
1739  */
1740 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1741 			     void *pb, int nonblocking)
1742 {
1743 	unsigned long flags;
1744 	int ret = 0;
1745 
1746 	/*
1747 	 * Wait for at least one buffer to become available on the done_list.
1748 	 */
1749 	ret = __vb2_wait_for_done_vb(q, nonblocking);
1750 	if (ret)
1751 		return ret;
1752 
1753 	/*
1754 	 * Driver's lock has been held since we last verified that done_list
1755 	 * is not empty, so no need for another list_empty(done_list) check.
1756 	 */
1757 	spin_lock_irqsave(&q->done_lock, flags);
1758 	*vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1759 	/*
1760 	 * Only remove the buffer from done_list if all planes can be
1761 	 * handled. Some cases such as V4L2 file I/O and DVB have pb
1762 	 * == NULL; skip the check then as there's nothing to verify.
1763 	 */
1764 	if (pb)
1765 		ret = call_bufop(q, verify_planes_array, *vb, pb);
1766 	if (!ret)
1767 		list_del(&(*vb)->done_entry);
1768 	spin_unlock_irqrestore(&q->done_lock, flags);
1769 
1770 	return ret;
1771 }
1772 
1773 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1774 {
1775 	if (!q->streaming) {
1776 		dprintk(1, "streaming off, will not wait for buffers\n");
1777 		return -EINVAL;
1778 	}
1779 
1780 	if (q->start_streaming_called)
1781 		wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
1782 	return 0;
1783 }
1784 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1785 
1786 /*
1787  * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1788  */
1789 static void __vb2_dqbuf(struct vb2_buffer *vb)
1790 {
1791 	struct vb2_queue *q = vb->vb2_queue;
1792 
1793 	/* nothing to do if the buffer is already dequeued */
1794 	if (vb->state == VB2_BUF_STATE_DEQUEUED)
1795 		return;
1796 
1797 	vb->state = VB2_BUF_STATE_DEQUEUED;
1798 
1799 	call_void_bufop(q, init_buffer, vb);
1800 }
1801 
1802 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
1803 		   bool nonblocking)
1804 {
1805 	struct vb2_buffer *vb = NULL;
1806 	int ret;
1807 
1808 	ret = __vb2_get_done_vb(q, &vb, pb, nonblocking);
1809 	if (ret < 0)
1810 		return ret;
1811 
1812 	switch (vb->state) {
1813 	case VB2_BUF_STATE_DONE:
1814 		dprintk(3, "returning done buffer\n");
1815 		break;
1816 	case VB2_BUF_STATE_ERROR:
1817 		dprintk(3, "returning done buffer with errors\n");
1818 		break;
1819 	default:
1820 		dprintk(1, "invalid buffer state\n");
1821 		return -EINVAL;
1822 	}
1823 
1824 	call_void_vb_qop(vb, buf_finish, vb);
1825 	vb->prepared = 0;
1826 
1827 	if (pindex)
1828 		*pindex = vb->index;
1829 
1830 	/* Fill buffer information for the userspace */
1831 	if (pb)
1832 		call_void_bufop(q, fill_user_buffer, vb, pb);
1833 
1834 	/* Remove from videobuf queue */
1835 	list_del(&vb->queued_entry);
1836 	q->queued_count--;
1837 
1838 	trace_vb2_dqbuf(q, vb);
1839 
1840 	/* go back to dequeued state */
1841 	__vb2_dqbuf(vb);
1842 
1843 	if (WARN_ON(vb->req_obj.req)) {
1844 		media_request_object_unbind(&vb->req_obj);
1845 		media_request_object_put(&vb->req_obj);
1846 	}
1847 	if (vb->request)
1848 		media_request_put(vb->request);
1849 	vb->request = NULL;
1850 
1851 	dprintk(2, "dqbuf of buffer %d, with state %d\n",
1852 			vb->index, vb->state);
1853 
1854 	return 0;
1855 
1856 }
1857 EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
1858 
1859 /*
1860  * __vb2_queue_cancel() - cancel and stop (pause) streaming
1861  *
1862  * Removes all queued buffers from driver's queue and all buffers queued by
1863  * userspace from videobuf's queue. Returns to state after reqbufs.
1864  */
1865 static void __vb2_queue_cancel(struct vb2_queue *q)
1866 {
1867 	unsigned int i;
1868 
1869 	/*
1870 	 * Tell driver to stop all transactions and release all queued
1871 	 * buffers.
1872 	 */
1873 	if (q->start_streaming_called)
1874 		call_void_qop(q, stop_streaming, q);
1875 
1876 	/*
1877 	 * If you see this warning, then the driver isn't cleaning up properly
1878 	 * in stop_streaming(). See the stop_streaming() documentation in
1879 	 * videobuf2-core.h for more information how buffers should be returned
1880 	 * to vb2 in stop_streaming().
1881 	 */
1882 	if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1883 		for (i = 0; i < q->num_buffers; ++i)
1884 			if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE) {
1885 				pr_warn("driver bug: stop_streaming operation is leaving buf %p in active state\n",
1886 					q->bufs[i]);
1887 				vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
1888 			}
1889 		/* Must be zero now */
1890 		WARN_ON(atomic_read(&q->owned_by_drv_count));
1891 	}
1892 
1893 	q->streaming = 0;
1894 	q->start_streaming_called = 0;
1895 	q->queued_count = 0;
1896 	q->error = 0;
1897 	q->uses_requests = 0;
1898 	q->uses_qbuf = 0;
1899 
1900 	/*
1901 	 * Remove all buffers from videobuf's list...
1902 	 */
1903 	INIT_LIST_HEAD(&q->queued_list);
1904 	/*
1905 	 * ...and done list; userspace will not receive any buffers it
1906 	 * has not already dequeued before initiating cancel.
1907 	 */
1908 	INIT_LIST_HEAD(&q->done_list);
1909 	atomic_set(&q->owned_by_drv_count, 0);
1910 	wake_up_all(&q->done_wq);
1911 
1912 	/*
1913 	 * Reinitialize all buffers for next use.
1914 	 * Make sure to call buf_finish for any queued buffers. Normally
1915 	 * that's done in dqbuf, but that's not going to happen when we
1916 	 * cancel the whole queue. Note: this code belongs here, not in
1917 	 * __vb2_dqbuf() since in vb2_core_dqbuf() there is a critical
1918 	 * call to __fill_user_buffer() after buf_finish(). That order can't
1919 	 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
1920 	 */
1921 	for (i = 0; i < q->num_buffers; ++i) {
1922 		struct vb2_buffer *vb = q->bufs[i];
1923 		struct media_request *req = vb->req_obj.req;
1924 
1925 		/*
1926 		 * If a request is associated with this buffer, then
1927 		 * call buf_request_cancel() to give the driver to complete()
1928 		 * related request objects. Otherwise those objects would
1929 		 * never complete.
1930 		 */
1931 		if (req) {
1932 			enum media_request_state state;
1933 			unsigned long flags;
1934 
1935 			spin_lock_irqsave(&req->lock, flags);
1936 			state = req->state;
1937 			spin_unlock_irqrestore(&req->lock, flags);
1938 
1939 			if (state == MEDIA_REQUEST_STATE_QUEUED)
1940 				call_void_vb_qop(vb, buf_request_complete, vb);
1941 		}
1942 
1943 		if (vb->synced) {
1944 			unsigned int plane;
1945 
1946 			for (plane = 0; plane < vb->num_planes; ++plane)
1947 				call_void_memop(vb, finish,
1948 						vb->planes[plane].mem_priv);
1949 			vb->synced = 0;
1950 		}
1951 
1952 		if (vb->prepared) {
1953 			call_void_vb_qop(vb, buf_finish, vb);
1954 			vb->prepared = 0;
1955 		}
1956 		__vb2_dqbuf(vb);
1957 
1958 		if (vb->req_obj.req) {
1959 			media_request_object_unbind(&vb->req_obj);
1960 			media_request_object_put(&vb->req_obj);
1961 		}
1962 		if (vb->request)
1963 			media_request_put(vb->request);
1964 		vb->request = NULL;
1965 		vb->copied_timestamp = 0;
1966 	}
1967 }
1968 
1969 int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
1970 {
1971 	int ret;
1972 
1973 	if (type != q->type) {
1974 		dprintk(1, "invalid stream type\n");
1975 		return -EINVAL;
1976 	}
1977 
1978 	if (q->streaming) {
1979 		dprintk(3, "already streaming\n");
1980 		return 0;
1981 	}
1982 
1983 	if (!q->num_buffers) {
1984 		dprintk(1, "no buffers have been allocated\n");
1985 		return -EINVAL;
1986 	}
1987 
1988 	if (q->num_buffers < q->min_buffers_needed) {
1989 		dprintk(1, "need at least %u allocated buffers\n",
1990 				q->min_buffers_needed);
1991 		return -EINVAL;
1992 	}
1993 
1994 	/*
1995 	 * Tell driver to start streaming provided sufficient buffers
1996 	 * are available.
1997 	 */
1998 	if (q->queued_count >= q->min_buffers_needed) {
1999 		ret = v4l_vb2q_enable_media_source(q);
2000 		if (ret)
2001 			return ret;
2002 		ret = vb2_start_streaming(q);
2003 		if (ret)
2004 			return ret;
2005 	}
2006 
2007 	q->streaming = 1;
2008 
2009 	dprintk(3, "successful\n");
2010 	return 0;
2011 }
2012 EXPORT_SYMBOL_GPL(vb2_core_streamon);
2013 
2014 void vb2_queue_error(struct vb2_queue *q)
2015 {
2016 	q->error = 1;
2017 
2018 	wake_up_all(&q->done_wq);
2019 }
2020 EXPORT_SYMBOL_GPL(vb2_queue_error);
2021 
2022 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
2023 {
2024 	if (type != q->type) {
2025 		dprintk(1, "invalid stream type\n");
2026 		return -EINVAL;
2027 	}
2028 
2029 	/*
2030 	 * Cancel will pause streaming and remove all buffers from the driver
2031 	 * and videobuf, effectively returning control over them to userspace.
2032 	 *
2033 	 * Note that we do this even if q->streaming == 0: if you prepare or
2034 	 * queue buffers, and then call streamoff without ever having called
2035 	 * streamon, you would still expect those buffers to be returned to
2036 	 * their normal dequeued state.
2037 	 */
2038 	__vb2_queue_cancel(q);
2039 	q->waiting_for_buffers = !q->is_output;
2040 	q->last_buffer_dequeued = false;
2041 
2042 	dprintk(3, "successful\n");
2043 	return 0;
2044 }
2045 EXPORT_SYMBOL_GPL(vb2_core_streamoff);
2046 
2047 /*
2048  * __find_plane_by_offset() - find plane associated with the given offset off
2049  */
2050 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
2051 			unsigned int *_buffer, unsigned int *_plane)
2052 {
2053 	struct vb2_buffer *vb;
2054 	unsigned int buffer, plane;
2055 
2056 	/*
2057 	 * Go over all buffers and their planes, comparing the given offset
2058 	 * with an offset assigned to each plane. If a match is found,
2059 	 * return its buffer and plane numbers.
2060 	 */
2061 	for (buffer = 0; buffer < q->num_buffers; ++buffer) {
2062 		vb = q->bufs[buffer];
2063 
2064 		for (plane = 0; plane < vb->num_planes; ++plane) {
2065 			if (vb->planes[plane].m.offset == off) {
2066 				*_buffer = buffer;
2067 				*_plane = plane;
2068 				return 0;
2069 			}
2070 		}
2071 	}
2072 
2073 	return -EINVAL;
2074 }
2075 
2076 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
2077 		unsigned int index, unsigned int plane, unsigned int flags)
2078 {
2079 	struct vb2_buffer *vb = NULL;
2080 	struct vb2_plane *vb_plane;
2081 	int ret;
2082 	struct dma_buf *dbuf;
2083 
2084 	if (q->memory != VB2_MEMORY_MMAP) {
2085 		dprintk(1, "queue is not currently set up for mmap\n");
2086 		return -EINVAL;
2087 	}
2088 
2089 	if (!q->mem_ops->get_dmabuf) {
2090 		dprintk(1, "queue does not support DMA buffer exporting\n");
2091 		return -EINVAL;
2092 	}
2093 
2094 	if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
2095 		dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
2096 		return -EINVAL;
2097 	}
2098 
2099 	if (type != q->type) {
2100 		dprintk(1, "invalid buffer type\n");
2101 		return -EINVAL;
2102 	}
2103 
2104 	if (index >= q->num_buffers) {
2105 		dprintk(1, "buffer index out of range\n");
2106 		return -EINVAL;
2107 	}
2108 
2109 	vb = q->bufs[index];
2110 
2111 	if (plane >= vb->num_planes) {
2112 		dprintk(1, "buffer plane out of range\n");
2113 		return -EINVAL;
2114 	}
2115 
2116 	if (vb2_fileio_is_active(q)) {
2117 		dprintk(1, "expbuf: file io in progress\n");
2118 		return -EBUSY;
2119 	}
2120 
2121 	vb_plane = &vb->planes[plane];
2122 
2123 	dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv,
2124 				flags & O_ACCMODE);
2125 	if (IS_ERR_OR_NULL(dbuf)) {
2126 		dprintk(1, "failed to export buffer %d, plane %d\n",
2127 			index, plane);
2128 		return -EINVAL;
2129 	}
2130 
2131 	ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
2132 	if (ret < 0) {
2133 		dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
2134 			index, plane, ret);
2135 		dma_buf_put(dbuf);
2136 		return ret;
2137 	}
2138 
2139 	dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
2140 		index, plane, ret);
2141 	*fd = ret;
2142 
2143 	return 0;
2144 }
2145 EXPORT_SYMBOL_GPL(vb2_core_expbuf);
2146 
2147 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
2148 {
2149 	unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
2150 	struct vb2_buffer *vb;
2151 	unsigned int buffer = 0, plane = 0;
2152 	int ret;
2153 	unsigned long length;
2154 
2155 	if (q->memory != VB2_MEMORY_MMAP) {
2156 		dprintk(1, "queue is not currently set up for mmap\n");
2157 		return -EINVAL;
2158 	}
2159 
2160 	/*
2161 	 * Check memory area access mode.
2162 	 */
2163 	if (!(vma->vm_flags & VM_SHARED)) {
2164 		dprintk(1, "invalid vma flags, VM_SHARED needed\n");
2165 		return -EINVAL;
2166 	}
2167 	if (q->is_output) {
2168 		if (!(vma->vm_flags & VM_WRITE)) {
2169 			dprintk(1, "invalid vma flags, VM_WRITE needed\n");
2170 			return -EINVAL;
2171 		}
2172 	} else {
2173 		if (!(vma->vm_flags & VM_READ)) {
2174 			dprintk(1, "invalid vma flags, VM_READ needed\n");
2175 			return -EINVAL;
2176 		}
2177 	}
2178 
2179 	mutex_lock(&q->mmap_lock);
2180 
2181 	if (vb2_fileio_is_active(q)) {
2182 		dprintk(1, "mmap: file io in progress\n");
2183 		ret = -EBUSY;
2184 		goto unlock;
2185 	}
2186 
2187 	/*
2188 	 * Find the plane corresponding to the offset passed by userspace.
2189 	 */
2190 	ret = __find_plane_by_offset(q, off, &buffer, &plane);
2191 	if (ret)
2192 		goto unlock;
2193 
2194 	vb = q->bufs[buffer];
2195 
2196 	/*
2197 	 * MMAP requires page_aligned buffers.
2198 	 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2199 	 * so, we need to do the same here.
2200 	 */
2201 	length = PAGE_ALIGN(vb->planes[plane].length);
2202 	if (length < (vma->vm_end - vma->vm_start)) {
2203 		dprintk(1,
2204 			"MMAP invalid, as it would overflow buffer length\n");
2205 		ret = -EINVAL;
2206 		goto unlock;
2207 	}
2208 
2209 	/*
2210 	 * vm_pgoff is treated in V4L2 API as a 'cookie' to select a buffer,
2211 	 * not as a in-buffer offset. We always want to mmap a whole buffer
2212 	 * from its beginning.
2213 	 */
2214 	vma->vm_pgoff = 0;
2215 
2216 	ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
2217 
2218 unlock:
2219 	mutex_unlock(&q->mmap_lock);
2220 	if (ret)
2221 		return ret;
2222 
2223 	dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
2224 	return 0;
2225 }
2226 EXPORT_SYMBOL_GPL(vb2_mmap);
2227 
2228 #ifndef CONFIG_MMU
2229 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
2230 				    unsigned long addr,
2231 				    unsigned long len,
2232 				    unsigned long pgoff,
2233 				    unsigned long flags)
2234 {
2235 	unsigned long off = pgoff << PAGE_SHIFT;
2236 	struct vb2_buffer *vb;
2237 	unsigned int buffer, plane;
2238 	void *vaddr;
2239 	int ret;
2240 
2241 	if (q->memory != VB2_MEMORY_MMAP) {
2242 		dprintk(1, "queue is not currently set up for mmap\n");
2243 		return -EINVAL;
2244 	}
2245 
2246 	/*
2247 	 * Find the plane corresponding to the offset passed by userspace.
2248 	 */
2249 	ret = __find_plane_by_offset(q, off, &buffer, &plane);
2250 	if (ret)
2251 		return ret;
2252 
2253 	vb = q->bufs[buffer];
2254 
2255 	vaddr = vb2_plane_vaddr(vb, plane);
2256 	return vaddr ? (unsigned long)vaddr : -EINVAL;
2257 }
2258 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2259 #endif
2260 
2261 int vb2_core_queue_init(struct vb2_queue *q)
2262 {
2263 	/*
2264 	 * Sanity check
2265 	 */
2266 	if (WARN_ON(!q)			  ||
2267 	    WARN_ON(!q->ops)		  ||
2268 	    WARN_ON(!q->mem_ops)	  ||
2269 	    WARN_ON(!q->type)		  ||
2270 	    WARN_ON(!q->io_modes)	  ||
2271 	    WARN_ON(!q->ops->queue_setup) ||
2272 	    WARN_ON(!q->ops->buf_queue))
2273 		return -EINVAL;
2274 
2275 	if (WARN_ON(q->requires_requests && !q->supports_requests))
2276 		return -EINVAL;
2277 
2278 	INIT_LIST_HEAD(&q->queued_list);
2279 	INIT_LIST_HEAD(&q->done_list);
2280 	spin_lock_init(&q->done_lock);
2281 	mutex_init(&q->mmap_lock);
2282 	init_waitqueue_head(&q->done_wq);
2283 
2284 	q->memory = VB2_MEMORY_UNKNOWN;
2285 
2286 	if (q->buf_struct_size == 0)
2287 		q->buf_struct_size = sizeof(struct vb2_buffer);
2288 
2289 	if (q->bidirectional)
2290 		q->dma_dir = DMA_BIDIRECTIONAL;
2291 	else
2292 		q->dma_dir = q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
2293 
2294 	return 0;
2295 }
2296 EXPORT_SYMBOL_GPL(vb2_core_queue_init);
2297 
2298 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2299 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2300 void vb2_core_queue_release(struct vb2_queue *q)
2301 {
2302 	__vb2_cleanup_fileio(q);
2303 	__vb2_queue_cancel(q);
2304 	mutex_lock(&q->mmap_lock);
2305 	__vb2_queue_free(q, q->num_buffers);
2306 	mutex_unlock(&q->mmap_lock);
2307 }
2308 EXPORT_SYMBOL_GPL(vb2_core_queue_release);
2309 
2310 __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
2311 		poll_table *wait)
2312 {
2313 	__poll_t req_events = poll_requested_events(wait);
2314 	struct vb2_buffer *vb = NULL;
2315 	unsigned long flags;
2316 
2317 	if (!q->is_output && !(req_events & (EPOLLIN | EPOLLRDNORM)))
2318 		return 0;
2319 	if (q->is_output && !(req_events & (EPOLLOUT | EPOLLWRNORM)))
2320 		return 0;
2321 
2322 	poll_wait(file, &q->done_wq, wait);
2323 
2324 	/*
2325 	 * Start file I/O emulator only if streaming API has not been used yet.
2326 	 */
2327 	if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2328 		if (!q->is_output && (q->io_modes & VB2_READ) &&
2329 				(req_events & (EPOLLIN | EPOLLRDNORM))) {
2330 			if (__vb2_init_fileio(q, 1))
2331 				return EPOLLERR;
2332 		}
2333 		if (q->is_output && (q->io_modes & VB2_WRITE) &&
2334 				(req_events & (EPOLLOUT | EPOLLWRNORM))) {
2335 			if (__vb2_init_fileio(q, 0))
2336 				return EPOLLERR;
2337 			/*
2338 			 * Write to OUTPUT queue can be done immediately.
2339 			 */
2340 			return EPOLLOUT | EPOLLWRNORM;
2341 		}
2342 	}
2343 
2344 	/*
2345 	 * There is nothing to wait for if the queue isn't streaming, or if the
2346 	 * error flag is set.
2347 	 */
2348 	if (!vb2_is_streaming(q) || q->error)
2349 		return EPOLLERR;
2350 
2351 	/*
2352 	 * If this quirk is set and QBUF hasn't been called yet then
2353 	 * return EPOLLERR as well. This only affects capture queues, output
2354 	 * queues will always initialize waiting_for_buffers to false.
2355 	 * This quirk is set by V4L2 for backwards compatibility reasons.
2356 	 */
2357 	if (q->quirk_poll_must_check_waiting_for_buffers &&
2358 	    q->waiting_for_buffers && (req_events & (EPOLLIN | EPOLLRDNORM)))
2359 		return EPOLLERR;
2360 
2361 	/*
2362 	 * For output streams you can call write() as long as there are fewer
2363 	 * buffers queued than there are buffers available.
2364 	 */
2365 	if (q->is_output && q->fileio && q->queued_count < q->num_buffers)
2366 		return EPOLLOUT | EPOLLWRNORM;
2367 
2368 	if (list_empty(&q->done_list)) {
2369 		/*
2370 		 * If the last buffer was dequeued from a capture queue,
2371 		 * return immediately. DQBUF will return -EPIPE.
2372 		 */
2373 		if (q->last_buffer_dequeued)
2374 			return EPOLLIN | EPOLLRDNORM;
2375 	}
2376 
2377 	/*
2378 	 * Take first buffer available for dequeuing.
2379 	 */
2380 	spin_lock_irqsave(&q->done_lock, flags);
2381 	if (!list_empty(&q->done_list))
2382 		vb = list_first_entry(&q->done_list, struct vb2_buffer,
2383 					done_entry);
2384 	spin_unlock_irqrestore(&q->done_lock, flags);
2385 
2386 	if (vb && (vb->state == VB2_BUF_STATE_DONE
2387 			|| vb->state == VB2_BUF_STATE_ERROR)) {
2388 		return (q->is_output) ?
2389 				EPOLLOUT | EPOLLWRNORM :
2390 				EPOLLIN | EPOLLRDNORM;
2391 	}
2392 	return 0;
2393 }
2394 EXPORT_SYMBOL_GPL(vb2_core_poll);
2395 
2396 /*
2397  * struct vb2_fileio_buf - buffer context used by file io emulator
2398  *
2399  * vb2 provides a compatibility layer and emulator of file io (read and
2400  * write) calls on top of streaming API. This structure is used for
2401  * tracking context related to the buffers.
2402  */
2403 struct vb2_fileio_buf {
2404 	void *vaddr;
2405 	unsigned int size;
2406 	unsigned int pos;
2407 	unsigned int queued:1;
2408 };
2409 
2410 /*
2411  * struct vb2_fileio_data - queue context used by file io emulator
2412  *
2413  * @cur_index:	the index of the buffer currently being read from or
2414  *		written to. If equal to q->num_buffers then a new buffer
2415  *		must be dequeued.
2416  * @initial_index: in the read() case all buffers are queued up immediately
2417  *		in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2418  *		buffers. However, in the write() case no buffers are initially
2419  *		queued, instead whenever a buffer is full it is queued up by
2420  *		__vb2_perform_fileio(). Only once all available buffers have
2421  *		been queued up will __vb2_perform_fileio() start to dequeue
2422  *		buffers. This means that initially __vb2_perform_fileio()
2423  *		needs to know what buffer index to use when it is queuing up
2424  *		the buffers for the first time. That initial index is stored
2425  *		in this field. Once it is equal to q->num_buffers all
2426  *		available buffers have been queued and __vb2_perform_fileio()
2427  *		should start the normal dequeue/queue cycle.
2428  *
2429  * vb2 provides a compatibility layer and emulator of file io (read and
2430  * write) calls on top of streaming API. For proper operation it required
2431  * this structure to save the driver state between each call of the read
2432  * or write function.
2433  */
2434 struct vb2_fileio_data {
2435 	unsigned int count;
2436 	unsigned int type;
2437 	unsigned int memory;
2438 	struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
2439 	unsigned int cur_index;
2440 	unsigned int initial_index;
2441 	unsigned int q_count;
2442 	unsigned int dq_count;
2443 	unsigned read_once:1;
2444 	unsigned write_immediately:1;
2445 };
2446 
2447 /*
2448  * __vb2_init_fileio() - initialize file io emulator
2449  * @q:		videobuf2 queue
2450  * @read:	mode selector (1 means read, 0 means write)
2451  */
2452 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2453 {
2454 	struct vb2_fileio_data *fileio;
2455 	int i, ret;
2456 	unsigned int count = 0;
2457 
2458 	/*
2459 	 * Sanity check
2460 	 */
2461 	if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2462 		    (!read && !(q->io_modes & VB2_WRITE))))
2463 		return -EINVAL;
2464 
2465 	/*
2466 	 * Check if device supports mapping buffers to kernel virtual space.
2467 	 */
2468 	if (!q->mem_ops->vaddr)
2469 		return -EBUSY;
2470 
2471 	/*
2472 	 * Check if streaming api has not been already activated.
2473 	 */
2474 	if (q->streaming || q->num_buffers > 0)
2475 		return -EBUSY;
2476 
2477 	/*
2478 	 * Start with count 1, driver can increase it in queue_setup()
2479 	 */
2480 	count = 1;
2481 
2482 	dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2483 		(read) ? "read" : "write", count, q->fileio_read_once,
2484 		q->fileio_write_immediately);
2485 
2486 	fileio = kzalloc(sizeof(*fileio), GFP_KERNEL);
2487 	if (fileio == NULL)
2488 		return -ENOMEM;
2489 
2490 	fileio->read_once = q->fileio_read_once;
2491 	fileio->write_immediately = q->fileio_write_immediately;
2492 
2493 	/*
2494 	 * Request buffers and use MMAP type to force driver
2495 	 * to allocate buffers by itself.
2496 	 */
2497 	fileio->count = count;
2498 	fileio->memory = VB2_MEMORY_MMAP;
2499 	fileio->type = q->type;
2500 	q->fileio = fileio;
2501 	ret = vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2502 	if (ret)
2503 		goto err_kfree;
2504 
2505 	/*
2506 	 * Check if plane_count is correct
2507 	 * (multiplane buffers are not supported).
2508 	 */
2509 	if (q->bufs[0]->num_planes != 1) {
2510 		ret = -EBUSY;
2511 		goto err_reqbufs;
2512 	}
2513 
2514 	/*
2515 	 * Get kernel address of each buffer.
2516 	 */
2517 	for (i = 0; i < q->num_buffers; i++) {
2518 		fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2519 		if (fileio->bufs[i].vaddr == NULL) {
2520 			ret = -EINVAL;
2521 			goto err_reqbufs;
2522 		}
2523 		fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2524 	}
2525 
2526 	/*
2527 	 * Read mode requires pre queuing of all buffers.
2528 	 */
2529 	if (read) {
2530 		/*
2531 		 * Queue all buffers.
2532 		 */
2533 		for (i = 0; i < q->num_buffers; i++) {
2534 			ret = vb2_core_qbuf(q, i, NULL, NULL);
2535 			if (ret)
2536 				goto err_reqbufs;
2537 			fileio->bufs[i].queued = 1;
2538 		}
2539 		/*
2540 		 * All buffers have been queued, so mark that by setting
2541 		 * initial_index to q->num_buffers
2542 		 */
2543 		fileio->initial_index = q->num_buffers;
2544 		fileio->cur_index = q->num_buffers;
2545 	}
2546 
2547 	/*
2548 	 * Start streaming.
2549 	 */
2550 	ret = vb2_core_streamon(q, q->type);
2551 	if (ret)
2552 		goto err_reqbufs;
2553 
2554 	return ret;
2555 
2556 err_reqbufs:
2557 	fileio->count = 0;
2558 	vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2559 
2560 err_kfree:
2561 	q->fileio = NULL;
2562 	kfree(fileio);
2563 	return ret;
2564 }
2565 
2566 /*
2567  * __vb2_cleanup_fileio() - free resourced used by file io emulator
2568  * @q:		videobuf2 queue
2569  */
2570 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2571 {
2572 	struct vb2_fileio_data *fileio = q->fileio;
2573 
2574 	if (fileio) {
2575 		vb2_core_streamoff(q, q->type);
2576 		q->fileio = NULL;
2577 		fileio->count = 0;
2578 		vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2579 		kfree(fileio);
2580 		dprintk(3, "file io emulator closed\n");
2581 	}
2582 	return 0;
2583 }
2584 
2585 /*
2586  * __vb2_perform_fileio() - perform a single file io (read or write) operation
2587  * @q:		videobuf2 queue
2588  * @data:	pointed to target userspace buffer
2589  * @count:	number of bytes to read or write
2590  * @ppos:	file handle position tracking pointer
2591  * @nonblock:	mode selector (1 means blocking calls, 0 means nonblocking)
2592  * @read:	access mode selector (1 means read, 0 means write)
2593  */
2594 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2595 		loff_t *ppos, int nonblock, int read)
2596 {
2597 	struct vb2_fileio_data *fileio;
2598 	struct vb2_fileio_buf *buf;
2599 	bool is_multiplanar = q->is_multiplanar;
2600 	/*
2601 	 * When using write() to write data to an output video node the vb2 core
2602 	 * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2603 	 * else is able to provide this information with the write() operation.
2604 	 */
2605 	bool copy_timestamp = !read && q->copy_timestamp;
2606 	unsigned index;
2607 	int ret;
2608 
2609 	dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
2610 		read ? "read" : "write", (long)*ppos, count,
2611 		nonblock ? "non" : "");
2612 
2613 	if (!data)
2614 		return -EINVAL;
2615 
2616 	if (q->waiting_in_dqbuf) {
2617 		dprintk(3, "another dup()ped fd is %s\n",
2618 			read ? "reading" : "writing");
2619 		return -EBUSY;
2620 	}
2621 
2622 	/*
2623 	 * Initialize emulator on first call.
2624 	 */
2625 	if (!vb2_fileio_is_active(q)) {
2626 		ret = __vb2_init_fileio(q, read);
2627 		dprintk(3, "vb2_init_fileio result: %d\n", ret);
2628 		if (ret)
2629 			return ret;
2630 	}
2631 	fileio = q->fileio;
2632 
2633 	/*
2634 	 * Check if we need to dequeue the buffer.
2635 	 */
2636 	index = fileio->cur_index;
2637 	if (index >= q->num_buffers) {
2638 		struct vb2_buffer *b;
2639 
2640 		/*
2641 		 * Call vb2_dqbuf to get buffer back.
2642 		 */
2643 		ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
2644 		dprintk(5, "vb2_dqbuf result: %d\n", ret);
2645 		if (ret)
2646 			return ret;
2647 		fileio->dq_count += 1;
2648 
2649 		fileio->cur_index = index;
2650 		buf = &fileio->bufs[index];
2651 		b = q->bufs[index];
2652 
2653 		/*
2654 		 * Get number of bytes filled by the driver
2655 		 */
2656 		buf->pos = 0;
2657 		buf->queued = 0;
2658 		buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2659 				 : vb2_plane_size(q->bufs[index], 0);
2660 		/* Compensate for data_offset on read in the multiplanar case. */
2661 		if (is_multiplanar && read &&
2662 				b->planes[0].data_offset < buf->size) {
2663 			buf->pos = b->planes[0].data_offset;
2664 			buf->size -= buf->pos;
2665 		}
2666 	} else {
2667 		buf = &fileio->bufs[index];
2668 	}
2669 
2670 	/*
2671 	 * Limit count on last few bytes of the buffer.
2672 	 */
2673 	if (buf->pos + count > buf->size) {
2674 		count = buf->size - buf->pos;
2675 		dprintk(5, "reducing read count: %zd\n", count);
2676 	}
2677 
2678 	/*
2679 	 * Transfer data to userspace.
2680 	 */
2681 	dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
2682 		count, index, buf->pos);
2683 	if (read)
2684 		ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2685 	else
2686 		ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2687 	if (ret) {
2688 		dprintk(3, "error copying data\n");
2689 		return -EFAULT;
2690 	}
2691 
2692 	/*
2693 	 * Update counters.
2694 	 */
2695 	buf->pos += count;
2696 	*ppos += count;
2697 
2698 	/*
2699 	 * Queue next buffer if required.
2700 	 */
2701 	if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
2702 		struct vb2_buffer *b = q->bufs[index];
2703 
2704 		/*
2705 		 * Check if this is the last buffer to read.
2706 		 */
2707 		if (read && fileio->read_once && fileio->dq_count == 1) {
2708 			dprintk(3, "read limit reached\n");
2709 			return __vb2_cleanup_fileio(q);
2710 		}
2711 
2712 		/*
2713 		 * Call vb2_qbuf and give buffer to the driver.
2714 		 */
2715 		b->planes[0].bytesused = buf->pos;
2716 
2717 		if (copy_timestamp)
2718 			b->timestamp = ktime_get_ns();
2719 		ret = vb2_core_qbuf(q, index, NULL, NULL);
2720 		dprintk(5, "vb2_dbuf result: %d\n", ret);
2721 		if (ret)
2722 			return ret;
2723 
2724 		/*
2725 		 * Buffer has been queued, update the status
2726 		 */
2727 		buf->pos = 0;
2728 		buf->queued = 1;
2729 		buf->size = vb2_plane_size(q->bufs[index], 0);
2730 		fileio->q_count += 1;
2731 		/*
2732 		 * If we are queuing up buffers for the first time, then
2733 		 * increase initial_index by one.
2734 		 */
2735 		if (fileio->initial_index < q->num_buffers)
2736 			fileio->initial_index++;
2737 		/*
2738 		 * The next buffer to use is either a buffer that's going to be
2739 		 * queued for the first time (initial_index < q->num_buffers)
2740 		 * or it is equal to q->num_buffers, meaning that the next
2741 		 * time we need to dequeue a buffer since we've now queued up
2742 		 * all the 'first time' buffers.
2743 		 */
2744 		fileio->cur_index = fileio->initial_index;
2745 	}
2746 
2747 	/*
2748 	 * Return proper number of bytes processed.
2749 	 */
2750 	if (ret == 0)
2751 		ret = count;
2752 	return ret;
2753 }
2754 
2755 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2756 		loff_t *ppos, int nonblocking)
2757 {
2758 	return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2759 }
2760 EXPORT_SYMBOL_GPL(vb2_read);
2761 
2762 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2763 		loff_t *ppos, int nonblocking)
2764 {
2765 	return __vb2_perform_fileio(q, (char __user *) data, count,
2766 							ppos, nonblocking, 0);
2767 }
2768 EXPORT_SYMBOL_GPL(vb2_write);
2769 
2770 struct vb2_threadio_data {
2771 	struct task_struct *thread;
2772 	vb2_thread_fnc fnc;
2773 	void *priv;
2774 	bool stop;
2775 };
2776 
2777 static int vb2_thread(void *data)
2778 {
2779 	struct vb2_queue *q = data;
2780 	struct vb2_threadio_data *threadio = q->threadio;
2781 	bool copy_timestamp = false;
2782 	unsigned prequeue = 0;
2783 	unsigned index = 0;
2784 	int ret = 0;
2785 
2786 	if (q->is_output) {
2787 		prequeue = q->num_buffers;
2788 		copy_timestamp = q->copy_timestamp;
2789 	}
2790 
2791 	set_freezable();
2792 
2793 	for (;;) {
2794 		struct vb2_buffer *vb;
2795 
2796 		/*
2797 		 * Call vb2_dqbuf to get buffer back.
2798 		 */
2799 		if (prequeue) {
2800 			vb = q->bufs[index++];
2801 			prequeue--;
2802 		} else {
2803 			call_void_qop(q, wait_finish, q);
2804 			if (!threadio->stop)
2805 				ret = vb2_core_dqbuf(q, &index, NULL, 0);
2806 			call_void_qop(q, wait_prepare, q);
2807 			dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
2808 			if (!ret)
2809 				vb = q->bufs[index];
2810 		}
2811 		if (ret || threadio->stop)
2812 			break;
2813 		try_to_freeze();
2814 
2815 		if (vb->state != VB2_BUF_STATE_ERROR)
2816 			if (threadio->fnc(vb, threadio->priv))
2817 				break;
2818 		call_void_qop(q, wait_finish, q);
2819 		if (copy_timestamp)
2820 			vb->timestamp = ktime_get_ns();
2821 		if (!threadio->stop)
2822 			ret = vb2_core_qbuf(q, vb->index, NULL, NULL);
2823 		call_void_qop(q, wait_prepare, q);
2824 		if (ret || threadio->stop)
2825 			break;
2826 	}
2827 
2828 	/* Hmm, linux becomes *very* unhappy without this ... */
2829 	while (!kthread_should_stop()) {
2830 		set_current_state(TASK_INTERRUPTIBLE);
2831 		schedule();
2832 	}
2833 	return 0;
2834 }
2835 
2836 /*
2837  * This function should not be used for anything else but the videobuf2-dvb
2838  * support. If you think you have another good use-case for this, then please
2839  * contact the linux-media mailinglist first.
2840  */
2841 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
2842 		     const char *thread_name)
2843 {
2844 	struct vb2_threadio_data *threadio;
2845 	int ret = 0;
2846 
2847 	if (q->threadio)
2848 		return -EBUSY;
2849 	if (vb2_is_busy(q))
2850 		return -EBUSY;
2851 	if (WARN_ON(q->fileio))
2852 		return -EBUSY;
2853 
2854 	threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
2855 	if (threadio == NULL)
2856 		return -ENOMEM;
2857 	threadio->fnc = fnc;
2858 	threadio->priv = priv;
2859 
2860 	ret = __vb2_init_fileio(q, !q->is_output);
2861 	dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
2862 	if (ret)
2863 		goto nomem;
2864 	q->threadio = threadio;
2865 	threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
2866 	if (IS_ERR(threadio->thread)) {
2867 		ret = PTR_ERR(threadio->thread);
2868 		threadio->thread = NULL;
2869 		goto nothread;
2870 	}
2871 	return 0;
2872 
2873 nothread:
2874 	__vb2_cleanup_fileio(q);
2875 nomem:
2876 	kfree(threadio);
2877 	return ret;
2878 }
2879 EXPORT_SYMBOL_GPL(vb2_thread_start);
2880 
2881 int vb2_thread_stop(struct vb2_queue *q)
2882 {
2883 	struct vb2_threadio_data *threadio = q->threadio;
2884 	int err;
2885 
2886 	if (threadio == NULL)
2887 		return 0;
2888 	threadio->stop = true;
2889 	/* Wake up all pending sleeps in the thread */
2890 	vb2_queue_error(q);
2891 	err = kthread_stop(threadio->thread);
2892 	__vb2_cleanup_fileio(q);
2893 	threadio->thread = NULL;
2894 	kfree(threadio);
2895 	q->threadio = NULL;
2896 	return err;
2897 }
2898 EXPORT_SYMBOL_GPL(vb2_thread_stop);
2899 
2900 MODULE_DESCRIPTION("Media buffer core framework");
2901 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
2902 MODULE_LICENSE("GPL");
2903